Q1, Power, hourly personnel of operations and corporate service are variable with respect to revenue, and the rest are all fixed. Due to the power expense and hourly personnel salaries directly depend on the hours.
Q2,
Items Month | Jan. | Feb. | Mar. | Power | Costs | $1,546 | $1,485 | $1,697 | | Hours | 329 | 316 | 361 | | Cost per hour | $4.70 | $4.70 | $4.70 | Operation Personnel | Costs | $7,896 | $7,584 | $8,664 | | Hours | 329 | 316 | 361 | | Cost per hour | $24 | $24 | $24 | Total cost per hour | $28.70 | $28.70 | $28.70 |

Q3,
Intercompany sales = 205 hours * $ 400 = 82,000
Commercial sales = 138 hours * $800 = 110,400
Total Variable Expense = (Power + operation hourly personnel) * hours = ($4.70+$24)*(205+138) = $9844.10
Contribution margin = Sales revenue – Variable costs = $192,400 - $9,844 = $182,556
Contribution Income Statement: Sales | | Intercompany sales | $82,000 | Commercial sales | $110,400 | Total | $192,400 | Less Variable Costs: | Power | $1,612 | Operations: hourly personnel | $8,232 | Contribution Profit | $182,556 | Contribution Margin | 95% | Less Fixed Expense: | Rent | $8,000 | Custodial services | $1,240 | Computer leases | $95,000 | Maintenance | $5,400 | Computer equipment | $25,500 | Office equipment and fixtures | $680 | Operations: salaried staff | $21,600 | System Development and maintenance | $12,000 | Administration | $9,000 | Sales | $11,200 | Sales promotion | $8,083 | Corporate services | $15,236 | Operating Profits | -$30,383 |

Q4,
Based on sales - variable costs - fixed costs = 0,
We set X equals commercial revenue hours, so we have:
(205 * $400 + $800X) – $28.7 * (205 + X) – $212939 = 0
And we get X = 177.40
Conclusion, 178 hours of computer use would be necessary to breakeven each month.